VINEGAR FERMENT AND ITS CONDITIONS OF LIFE. 37 



ment of the formation of mold is indicated by the appearance of 

 white dots and then transferring the wine to a room having a 

 temperature of 86 F. At this temperature the development of 

 the vinegar ferment proceeds so vigorously that it suppresses the 

 mold ferment, and the peculiar mass constituting the mother of 

 vinegar soon forms upon the surface. 



Mother of vinegar occurs so generally in young wine (which 

 is chiefly used for the preparation of wine vinegar) that its for- 

 mation was considered as inseparably connected with that ot 

 acetic acid from alcohol, while actually it is only due to the pecu- 

 liar constitution of the fluid to be converted into vinegar. In 

 many places this opinion is still entertained, and especially where, 

 as is generally the case, the manufacture of vinegar from wine is 

 yet carried on in the primitive way of centuries ago. In speaking 

 of the preparation of vinegar from wine, it will be shown that the 

 conversion can be effected by means of the ordinary vinegar 

 ferment without the appearance of mother of vinegar. 



Summary. 



Briefly stated the points of the theoretical conditions of the 

 formation of vinegar of importance to the manufacturer are : 



1. Acetic acid is formed during many chemical conversions; 



for the manufacture of acetic acid, and consequently of 

 vinegar on a large scale, only two methods are available, 

 viz., the preparation of vinegar from alcohol by fermenta- 

 tion, or the obtaining of acetic acid by dry distillation of 

 wood. 



2. All alcoholic fluids formed by vinous fermentation of saccha- 



riferous plant juices or fermented malt extracts are suitable 

 for the preparation of vinegar by fermentation. Specially 

 prepared mixtures of water, alcohol, and vinegar may 

 also be used for the purpose, provided they contain small 

 quantities of certain organic substances and salts, and not 

 over 14 per cent, of alcohol. 



3. The acetous fermentation is induced by a microscopic organ- 



ism belonging to the bacteria, and the conversion of the 

 alcohol into acetic acid is in a certain ratio to the aug- 

 mentation of this organism. 



